Braxton Hicks?

Yesterday my boyfriend and I went on a walk because it was gorgeous outside and stopped because I was having really bad cramps. We stopped for 15 minutes because I felt like I couldn't move and that I was going to puke. They were about 7 minutes apart and I felt like my back was holding 50 pounds of pressure. They haven't stopped and I still have them today. They are really low and feel like sharp pains down there. Are these Braxton hicks?